An exciting new study, published by researchers at Yale University in conjunction with Precision Therapeutics, shows that an assay, called ChemoFx, could effectively inform physicians on the best possible treatment to fight epithelial ovarian cancer, individualized to the patients’ unique cancer cells.
Currently, physicians treat cancer patients empirically. This means that they choose a treatment regimen based on the results from previous patients with similar cancers. The physicians choose the treatment that has had the highest percentage of success in a previous population, but there is no guarantee that this treatment will work in any one individual because the physician has no information about that individual’s cancer.
The genetics of each individual patient’s cancer varies, sometimes widely. That is why a treatment that may work well for one patient is not successful in another patient. Of course, common themes do emerge within specific types of cancer, but for many of the most common types of cancer (e.g., breast cancer, lung cancer, colorectal cancer), many different genetic changes have been identified. Now, physicians may be able to acquire and use some of that knowledge to choose the best treatment for each individual patient.
A chemoresponse assay is a laboratory test that is performed on the cancer cells from a biopsy to evaluate the efficacy of a panel of cancer treatments. The use of a chemoresponse assay to assess the therapy choices before treatment begins is very promising; however previous studies have reported varied results and some of the data from these studies is considered controversial. The data have even been dismissed as useless by some. However, a similar assay is routinely used to test the antibiotic sensitivity of infections, which suggests that such a chemoresponse assay is feasible. Because of the growing number of approved chemotherapies, empirical treatment decisions are becoming more difficult. Thus, there is a great need for an assay that can deliver personalized care.
The researchers at Yale University and Precision Therapeutics hypothesized that a chemoresponse assay would be a good indicator of which treatments are likely to be successful in individual patients. In this prospective study, they collected biopsies from patients with recurrent epithelial ovarian cancer and used the cells from that biopsy to test the efficacy of 15 different treatments. They ranked each cancer as sensitive or resistant to each treatment. The physicians treating the patients, however, were blinded to the results of the assay. In other words, they continued to treat the patients empirically and without this information about the cancer. At the end of the study, the survival rates of patients were compared, based on which treatment they had received and whether their cancer had shown sensitivity to the treatment in the chemoresponse assay.
The results were very promising: patients with a tumor response defined as “sensitive” to the clinical treatment they had received demonstrated significantly improved progression-free survival . This suggests that a test performed with a patient’s cancer cells in a laboratory can predict which treatment will work best in their body to fight the cancer. Additional testing showed that more than half of patients may benefit from an assay-informed, individualized chemotherapy. In other words, informed decisions based on this information could double the success of treatments in the future.
The results of this study can be found in the journal Gynecologic Oncology, published by Elsevier. Precision Therapeutics, a life-science company based out of Pittsburgh, PA, is the producer of ChemoFx and financially supported this study.
Certainly, additional studies are needed, particularly to directly test the effect of informed treatment decisions on patient outcome, as well as to test additional cancer types. However, it is becoming clear that, as chemoresponse assays like ChemoFx develop and improve, they will be increasingly useful to assist physicians in the care of their cancer patients.
Rutherford T, Orr J, Grendys E, et al. A prospective study evaluating the clinical relevance of a chemoresponse assay for treatment of patients with persistent or recurrent ovarian cancer [published online ahead of print August 13, 2013]. Gyn Oncol. doi:10.1016/j.ygyno.2013.08.009.